Đáp án:

1. a) 180;144;192

          144=2⁴x3²

                180=2²x3²x5

          192=2⁶x3

ƯCLN(144;192;180)=2²x3=12

=) ƯC(144;192;180=Ư(12)={ 1;2;3;4;6;12}

b)350;420;560

          350=2x5²x7

          420=2²x3x5x7

          560=2⁴x5x7

ƯCLN(350;420;560)=2x5x7=70

=)ƯC(350;420;560)=Ư(70)={x ∈ N^*/x ≤ 70}

c)24;78;42

          24=2³x3

          78=2x3x13

          42=2x3x7

ƯCLN(24;78;42)=2x3=6

=) ƯC(24;48;72)=Ư(6)={1;2;3;6}

1. d) 15;9;45

          15=3x5

          9=3²

          45=3²x5

BCLN(15;45;9)=3²x5=45

=)BC(15;9;45)=B(45)={0;45;90;135;180;...}

CHÚC BẠN HỌC TỐT

CHO MÌNH XIN CÂU TRẢ LỜI HAY NHẤT VÀ 5 SAO NHÉ, THANK YOU :))

`a)` - Ta có :

`144=2^4 .3^2`

`180=2^2 .3^2 .5`

`192=2^6 .3`

`=> ƯC LN(144,180,192)=2^2 .3=12`

`=> ƯC(144,180,192)=Ư(12)={1;2;3;4;6;12}`

`b)` - Ta có :

`350=2.5^2 .7`

`420=2^2 .3.5.7`

`560=2^4 .5.7`

`=> ƯC LN(350,420,560)=2 .5.7=70`

`=> ƯC(350,420,560)=Ư(70)={1;2;5;7;10;14;35;70}`

`c)` - Ta có :

`24=2^3 .3`

`78=2.3.13`

`42=2.3.7`

`=> ƯC LN(24,78,42)=2.3=6`

`=> ƯC(24,78,42)=Ư(6)={1;2;3;6}`

`d)` - Ta có :

`15=3.5`

`9=3^2`

`45=3^2 .5`

`=> BCN N(15,9,45)=3^2 .5=45`

`=> BC(15,9,45)=B(45)={0;45;90;135;180;...}`